Driver Issue - Nvidia 560

So this morning I started getting the IRQL_NOT_LESS_OR_EQUAL BSOD error.

As per this forums advice of downloading driver cleaner to get rid of some old driver files still kicking around (which there were) and rebooting my PC as told to afterwards I now can't get past the Windows loading screen before getting stuck with a black with a thin blue bar going horizontally across the top. I'm assuming this is because I've knocked out a part of the driver I was using and it now cannot boot any graphics driver. To reitterate, I absolutely cannot reach the desktop currently.

In fact, I'm sure I've had this happen before with another graphics card that I was trying to put into my PC without the right drivers for it, so I'm 99.9% sure it's that the drivers are having an error.

It's my brothers old card (ASUS Nvidia 560) which he can't find the discs for to install the driver but my other brother is on his way home and he also runs a 560 so hopefully his CD will work, so my main question is: If he still has his CD which he should do because he's more responsible how do I install it if I can't get to the desktop and putting a different card in doesn't stop the black screen crashes?

Is it possible that it's not a graphics card error but a general graphics error of the PC itself?

If his CD doesn't work then what are my options? I also can't boot in safe mode, the error still occurs, and I can't boot the PC without the card in to download the drivers because then I have no visual display on the screen with which to do so.. I have a laptop I can download stuff on and a USB stick to transfer anything if needed etc.